The president was speaking a day after the NIE assessment became public. It found that Iran had halted work on a covert nuclear weapons program four years ago — though an NIE two years ago said Iran was at work on such a program.

Bush credited international pressure for the apparent halt of the program, and said it had to be maintained.

He rebuffed reporters' suggestions that he and the U.S. had lost credibility on such matters because of the failure to find weapons of mass destruction in Iraq.